Flat shaft control device



Nov, 12, 1940. H. w. RUBINSTEIN FLAT SHAFT CONTROL DEVICE Filed April 3,1939 2 Sheets-Sheet 1 Q SE INVENTOR. BY Qawz/ @ubiQSC-QQ ATTORNEY.

Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE FLAT SHAFTCONTBOL'DEVIOE Harry W. Rubinstcim Milwaukee, Wis., assignor toGlobe-Union, Inc., Milwaukee, Wis., a corporation of DelawareApplication April 3, 1939, Serial No.

11 Claims. (01. 64-4) This invention relates to an improvement in acontrol or operating device of the type commonly used on electricalapparatus or appliances as for example, on a radio receiver forcontrolling the '5 volume of the reception or reproduction or forisfactory to employ a shaft of flat wire or equivalent flat metal stock,one which may be punched or-cut from a sheetor strip of metal veryuickly and very readily and very inexpensively so that in the finalstructure there is a substantial saving in cost of production as well asin the amount oi material or metal used. Not only is this advan: tagerealized but the structural elements which combine the flat stock shaftwith the volume control are also punch press parts. The necessity ofmanufacturing elements on the screw ma- 40 chin or the resort tosimilarly expensive and time consuming operations are entirely avoided.Nevertheless in the assembly the flat wire shaft is firmly andeffectively supported for rotative adjustment and will not wabbl orspring or vibrate or be otherwise disadvantageous when employed on aradio receiver. Another object is to provide a bushing and controlmounting arrangement adapted for use with various types of volumecontrols and possessed of 50 the distinct advantage of simplifying,compacting and rendering less expensive the cost of production of suchdevices and yet rendering the device susceptible of ready production andof easy and ready and practical assembly to the chassis of a radioreceiver.

Other objects and advantages reside in certain novel features of theconstruction, arrangement, and combination of parts which will behereinafter more fully described and particularly pointed out in theappended claims, reference being panel of the radio, at which point itis interconvide a structure adapted to be conveniently suphad to theaccompanying drawings forming a part of this specification, and inwhich: I

Figure 1 is a view partly in side elevation and partly 'in centralvertical cross section showing a control device embodying the presentinvention;

Figure 2 is a group view in perspective showing the shaft and itsmounting sleeve prior to assembly with the bushing of a volume control;

Figure 3 is a View in end elevation lopking toward the right hand end ofFigure 1 but showing the cover of the control removed and illustratingparts broken away toshow the metal of the volume control;

Figure 4 is a fragmentary view partly in central vertical section andpartly in side elevation showing a modified form of the invention;

Figure 5 is a view similar to Figure 4 but showing still another form ofthe invention;

Figure 6 is a View similar to Figures 3 and 4 but illustrating thefourth modification of the invention;

Figure 7 is a view similar to Figure 6 but showing still another form ofthe invention;

Figure 8 is a view in end elevation looking toward the left hand end ofFigure 9, parts being broken away, the parts being shown in section forthe sake of illustration;

Figure 9 is a view similar to Figure 6 but showing still another form ofthe invention;

Figure 10 is a view illustrating how the structure may be adapted foruse with extension shafts;

Figurell is a fragmentary view in top plan of the central portion or"the structure shown in Figure 10.

Figure 12 is a fragmentary view partly in side elevation and partly incentral vertical cross section showing still another embodiment of theinvention,

Figure 13 is a fragmentary group view in perspective of the complementalsections of a shaft in another embodiment of the invention; and

\ Figure 14 is a view show-ing the shaft structure illustrated in Figure13 assembled and combined with an adjustable resistor.

Referring to the drawings and more particularly to Figures 1 to 3, itwill be seen that in the embodiment of the invention therein describedthe volume control is designated generally at [0 and is of the typehaving a casing or housing ll of insulating material-which is equippedwith a metal cover 12 having extensions l3 terminating in tabs H whichare bent around or clinched over to secure the cover in place. Thestructure of the volume control per se forms nopart of the presentinvention but it may be well to point out that it usually includes aresistance element It in the form of a carbonaceous or' conductivecoated strip of paper of similar flexible material across which amovable contact i5 is adjusted.

The rotation .of the movable contact is efiected by means of anoperating shaft designated generally at I 6, which extends from thevolume control through the front panel I! of the radio re-- ceiver, theprojecting end of the shaft having a knob l8 suitably attached theretoso as to facilitate turning of the operating or control shaft. In thepresent instance the volume control has a fixed bushing 20 combinedtherewith in a special way. This bushing is made up of a piece ofcylindrical sheet metal tubing, the inner end of which extends throughan opening in the back wall of the casing and is flanged or spun over asindicated at 2i. A mounting plate 22 is provided and has a centralopening which fits over the bushing 20, the mounting plate beingdisposed flush up against the adjacent end wall of the housing II. Tosecure the mountin plate 22 to the housing and also fasten the bushing20 in position, the bushing is provided with a corrugation 23 whichengages the mounting plate 22 around the margin of its opening so thatwhen the flange 2i is formed or spun during the assembly of the partsit, together with the corrugation 23, will clamp the mounting platefirmly to the housing as well as secure the bushing in position. In use,the bushing 20 is inserted through an opening in a supporting member 24which may be a part of the chassis of the radio receiver and tabs orlugs 25 formed integral with the mounting'plate 22 extend through slotsin v this supporting member and are bent or clinched over as shown inFigure 1. An insulating washeror layer 24' may be interposed between themounting plate 22 and the chassis or supporting member 24.

'One of the important features of the present invention resides in theuse of an operating shaft iii of flat stock and in the means providedfor rotatably supporting such a shaft. In the present embodiment of theinvention this is accomplished by providing a mounting sleeve 26 ofcylindrical form and designed to be a. snug rotating fit in the bushing20. The inner end of the mounting sleeve is provided with an endwall 21in which a diametrically extending slot 28 is formed. The out r end ofthe mounting sleeve is provided with an outwardly extending flange 29provided at diametrically opposite points with notches ill. When themounting sleeve is assembled with its bushing 20 its flange 29 rides onthe outer end of the bushing 20.

The inner end of the shaft I6 is provided with steps or reduced portions2| and 32 and there are shoulders 33 presented at the juncture of thereduced portions or step I] andfthe main portion of the shaft iii. Inthe assembly these shoulders 33 positively interflt with the notches 30of the flange 29. Theedges 3|a of the step 3| engage opposed portions ofthe inner peripheral wall of the mounting sleeve and the inner endportion of the step ii is a. snug fit in the diametric-sldt 2a of theend wall 21. The step :2-

extends through a slot provided therefor in the carrier 15' for themovable contact I5 and is upset or riveted over' into secure engagementtherewith: as indicated at u. Interfltting the shaft and mounting sleevein this way precludes any wobbling 'or transverse displacement of theflat shaft. The engagement of the -shoulders 33 s and the notches 30also preventsaxla'l shifting of the shaft Ii tothe right, as viewed inFigure 1. The connection between the inner end of the shaft I6 and thecontact carrier l5 p ev nts axial shifting of the shaft l8 in theopposite direction.

The shaft is thus supported in a steady and secure fashion, though forfree rotation, notwithstanding that it is made of flat stock or flatwire and is supported by cylindrical parts which are interfltted forturning movement with respect to each other.

The shaft IS with its steps 3| and 32, the eyelet 26 with its end wall21 and slot 28 and also with its flange 29 and notches, 3 0 are employedin all embodiments of the invention and are related and combined in justthe manner above described.

The several embodiments of the invention differ from each other in theconstruction of, or in the manner of combining the fixed bushing with,the volume control, or in the manner of supporting the assembly on thechassis of the radio re ceiver. In one instance, there is alsoillustrated the capability of the structure for use with extensionshafts.

In the structure shown in Figure 4 the fixed bushing is made up of aneyelet 33' having its inner end spun or flanged over the margin of theopening in the adJacent end wall of the housing and having its outer endspun or flanged over a collar 34 fitted over the projecting portion ofthe bushing 33' and having a base flange 35 flushly engaging themounting plate. In other respects the structure of the embodiment shownin Figure 4 is similar to that shown in Figure 1.

Figure 5 illustrates that the fixed bushing designated at 40'may bemoulded as one piece with the insulating housing of the volume control,the bushing receiving the eyelet 26 which coacts therewith and with theshaft l6 as before. With such a construction securing tabs H, integralwith the extensions 42 of the metal cover 43' of the volume control l0,coact with the chassis 24 of the radio receiver to secure the assemblyin position.

In the structure shown in Figure 6 the housing of the volume control isprovided with a machined fixed bushing 45 which coacts with the nut 46to secure the assembly in position. The

' mounting sleeve 28 is combined with the fixed it employs an eyelet 33for its fixed bushing. It

diflers from the form shown in Figure 4 in that the collar 24'corresponding to collar 34 is formed as an integral part of the mounting.plate 22 rather than as a separate piece. In the form of the inventionshown in Figures 8 and 9 the flxed bushing designated at 50 is spun outas an integral portion of the casing II of the volume'control device andextends through the opening in the chassis of the radio'receiver. Tabs,52. struck from the metal casing of the volume control are clinched overslots in the chassisto support the assembly in position.

Figures 10 and i1 illustrate any of the foregoing structures mayreadily'be combined with an extension shaft 62 of circular form.- Thisis rounding the slot. The shaft I4 is cut of! and is provided withnotches I1 designed to be alined 'with the grooves" so that when theparts are interfltted a snap ring I. may be employed to releasablysecure them assembled. Preferably also the extreme outer end of theshaft I6 is formed with a reduced extension l8 fltted ,or

pil d Ina socket ur in the shaft n.

I be achieved without the use of the mounting" In the form of theinvention shown in Figure 12 the volume control In is shown as being ofthe same general type illustrated in Figures 1 to 3, although the metalcover is not shown, but in practice is supplied and functions as inFigure-1 to secure the insulating casing ll of the control to themounting plate 22 as before, and tabs 25 on the mounting plate fastenthe assembly to the chassis 24. The fixed bushing designated in Figure12 at 62, is formed integral with the mounting plate. In this form ofthe invention instead of a single mounting sleeve or rotating bushing,two mounting sleeves or rotating bushings designated ,atBlI and BI areprovided. These mounting sleeves-are fitted over the steps of the end ofthe shaft 16 and are a close working rotative fit in the fixed bushing62. The mounting sleeve 60 has an outwardly directed angular flange 63at its outer end which is in rotative engagement with the outer end ofthe fixed bushing 62 and which abuts a shoulder 33 on the shaft I6 asbefore. However, the notches 30 are omitted as they are not necessarywhen two mounting sleeves are employed.

The inner end of the mounting sleeve 60 is formed with an integral endwall which has a diametrical slot through which the associated portionof the shaft I 6 extends and in which such portion of the shaft issnugly fitted. The inner mounting sleeve 6| has its outer end formedwith an integral end wall which has a diametrical slot receiving thestep at the extreme inner end.

of the shaft IS. The inner end of this mounting sleeve 6| has theportions thereof at the ends of its diametrical slot abutting a shoulderformed on the shaft 16 by the adjacent steps thereof. The extreme innerend of the shaft I6 is connected to' the rotatable members of the volumecontrol.

By having two bushings or mounting sleeves it is convenient andeconomical to closely control the diameter thereof so that they are asnug it is not necessary to accurately control their length. Iihisfacilitates and renders much more economical the production of theeyelets.

Some of the advantages of the invention may sleeves or bushings byspecially constructing the flat stock shaft and providing it in twocomplemental sections. For example, as illustrated in Figures 13 and 14,a short shaft section of fiat stock designated at 10 may be provided.This short section has its one end reduced as at 10' and upset orotherwise suitably secured to the adjustable member H of the adjustableresistor 12. The housing of this resistor may be supportedv in anysuitable way on the chassis or supporting member 13 and usuallyit hassome form of fixed bushing 14 extending through an opening in thechassis and secured in position in some suitable way as for instance, bymeans of a nut 15. 'I\he short shaft section 10 is provided at its outerend with a longitudinally extending slot 'Iii'andv also has spacednotches ll in its opposite edges, the notches being transversely alined.Cooperable with theshort shaft section 10 is an elongated shaft sectionalso of fiat stock and ofany suitable length. To one end of Both of theshaft sections and their edges form with a radius struck on the arccorresponding to that of the fixed bushing in which they are fitted inthe assembly. The shaft sections are assembled in the manner illustratedin Figure 14, that is, with their slots interfitted and the portions ofthe sections on the oppositesides of the slots overlapping unslottedportions of the shaft sections. When assembled the shaft sections aredisposed at right angles to each other and their notches 11 and 82 arealined to receivesnap rings 83 and 84 which are employed to maintainthem assembled and also to maintain the shaft assembly against axialmovement in its position.

While I have shown and described several constructions in which theinvention may be advantageously embodied, it is to be understood thatthe constructions shown have been selected merely for the purpose ofillustration or example and that various changes in the size, shape andarrangement of the parts may be made without departing from the spiritof the invention or the scope of the subjoined claims.

v The invention claimed is:

1. In combination with an electrical control device including a casingand a rotatable control element in said casing, a mounting bushingsecured to and projecting from the casing, an operating shaft for saidcontrol element, said shaft being of fiat stock, and a mounting sleevehaving a rotative fit in the bushing and having its inner end closed andprovided with 2. diametrical slot, the outer end of said mounting sleevehaving an outwardly directed annular flange in rotative engagement withtheouter end of the bushing and provided with diametrically oppositenotches, said shaft having a stepped portion extending through saidmounting sleeve and into the casing, the step disposed in said mountingsleeve having its edges engaged with the inner peripheral wall of saidmounting sleeve and fitted snugly in said slot, the juncture of saidstep and the main portion of the shaft presenting shoulders interfittedwith said notches and acting conjointly with said interfitted step andslot and with the engagement of said edges with the inner peripheralwall of said mounting sleeve to secure the shaft against any transversedisplacement with respect to said mounting sleeve ing, a cylindricalbushing secured to and projecting' from the casing, a cylindricalmounting sleeve rotatively fitted in the bushing and having an end wallat its inner end provided with 2. diametric slot, 'the'outer end of saidmounting sleeve being provided with an outwardly directed angu larflange riding on the outer end of the bushing, said flange havingdiametrically opposite notches, and a shaft of fiat stock having a re--duced end extending through said mounting sleeve and through the slot inthe inner end wall thereof; and being of such. width that its edgesvsnugly engage the inner periphery of said mounting sleeve and the endwalls of said slot; the

shoulders at the juncture of said reduced portion and the main portionof the shaft being interfltted with said notches.

3. In combination with a device having a casing,'a cylindrical bushingsecured to and projecting fronr the casing, a cylindrical mountingsleeve rotatively fitted in the bushing and having an end wall at itsinner end provided with a diametric slot, the outer endv of saidmounting sleeve being provided with an outwardly directed angular flangeriding on the outer'end of the bushing, said flange having diametricallyopposite notches, and a shaft of flat stock having a reduced endextending through said mounting sleeve and through the slot in the innerend wail thereof, and being of such width that its edges snugly engagethe inner periphery of said mounting sleeve and the end walls of saidslot, the shoulders at the juncture of said-reduced portion and the mainportion of the shaft being interfltted with said notches, saidinterfltting of the shoulders with said notches preventing axialmovement of the shaft in one direction, and means cooperable with theinner end of the shaft and preventing axial movement thereof in anopposite direction.

4. In combination with an electrical control ing flange riding on an endof the bushing, said flange being provided with notches in opposedportions thereof, and.an operating shaft of flat stock having a portioninterfitting with said notches and having edges of'another portion insnug engagement with the inner peripheral wall of said mounting sleeveand also having a portion snugly interfitted withsaid slot, the innerend of the shaft being interconnected with said control element andsecured thereto.

5. A device of the character described comprising a casing having acylindrical bushing projecting therefrom and fixed thereto, a rotatablebushing supported in the fixed bushing and having a flange at its outerend riding on the outer end of thefixed bushing and provided withnotches, the-inner end of the rotating bushing having an end wallprovided with a transverse slot alined with the notches of the flange,and an operating shaft of fiat wire stock having a portiora ninterfittedwith the notches and having a sm er portion engaged with the innerperiphery of the rotative bushing and snugly: fitted in having edges ofanother portion in snug engagement with opposed portions of theinnerperipheral wall of said' mounting sleeve and also snugly engaged withsaid slotted end wall.

'7. In combination with an electrical control device including a casingand a rotatable control element in said casing, a mounting bushingsecured to the casing and projecting therefrom, an operating shaft forsaid control element, said shaft being of flat stock, and a mountingsleeve having a rotative fit in the bushing and having its inner endclosed and provided with a diametsnugly fitted in said slot, thejuncture of said step and the main portion of the shaft presentingshoulders interfitted with said notches and acting conjointly with saidinterfitted step and slot and with the engagement of the edges with theinner peripheral wall of said mounting sleeve to secure the shaftagainst any transverse displacement with respect to said mounting sleeveor its bushing, the inner end of the shaft having anotherstep beingsecured to said rotatable control element to provide a drivingconnection between it and the shaft.

8. A control device of the character described comprising a casinghaving a bushing fixedly connected thereto and projecting therefrom, amounting sleeve rotatably fitted in the bushing and having an end wallat its inner end provided with a slot and also having an outwardlydirected annular flange at its outer end provided with notches, anoperating shaft of fiat stock positively connected with the notches ofthe flange andthe slot of the inner end wall, and a connection betweenthe inner end of the shaft and the element to be controlled.

9. A control device of the character described comprising a casinghaving a bushing fixedly connected thereto and projecting therefrom, amounting sleeve rotatably fitted in the bushing and having an end wallat its inner end provided with a slot and also having an outwardlydirected annular flange at its outer end provided with notches, anoperating shaft of fiat stock positively connected with the notches ofthe flange and the slot of the inner end wall, a connection between theinner end of the shaft and the element to be controlled, and meanscooperable with the bushingto support the assembly on a fixed support.

10. A control device of the character described comprising a casinghaving a fixed bushing, a hollow cylindrical mounting. 'sleeve rotatablysupported in said bushing, said mounting sleeve being provided with anend wall, a diametrical slot formed in said wall, and an operating shaftof fiat stock extending within said sleeve,- portions of the edges ofsaid shaft being engaged with the inner peripheral wall of said sleeve,the sides'of said shaft being engaged with said slot.

' 11, A control device of the character described comprising a casinghaving a fixed bushing, a

hollow cylindrical mounting sleeve rotatably sup-- ported in saidbushing, said sleeve having an outwardly directed annular flange havingrotative engagement with the end of said bushing, and-an operatingshaftof fiat stock extending within said sleeve and having portions ofits edges in engagement with the inner peripheral wall of said sleeve,there being interlocking means between said flange and said shaft toprevent relative 'rotative movement therebetween.

HARRY w. RUBINSTEIN.

